Multi parameter cell analysis and cell sorting will be used by the PI and seven coinvestigators in several projects derived from experience with a simplified flow cytometer (FACS-III). These more sophisticated projects require state-of-the-art equipment to achieve desired information. Both analaytical and cell sorting uses are proposed. 1) Multi parameter analysis (MPA) will be used to understand the cells present in the murine analogue of human chronic lymphocytic leukemia (CLL)(BCL1). Sorting of components of the complex mixture will establish malignant potential of subsets of the tumor cell population. 2) In human disease, MPA will assist in determining the population of cells present in CLL with respect to co-varience of surface markers in the tumore cell population (Ia, FcR, HLA, Ig, CR). Attempts will be made to relate findings of surface phenotype of the tumor population to natural history of the patient. 3) Flow cytometry has been used for tumor detection by staining of periphral blood with anti light chain sera (Kappa and Lambda). MPA should provide greater sensitivity by allowing introduction of new surface markers, (heavy chains, CR, Ia, Lhla, FcR). 4) MPA will be used to determine stages in the activation of lymphocytes of human and mouse by mitogen or antigen. The manner in which immunoregulation is expressed can be determined from such studies. 5) MPA will be used to study differentiation of a human pre-B cell line induced by a variety of agents. Markers for differentiation will include surface and cytoplasmic Ig and determinants, nuclear TdT, Ia, T65, B-1, Fc receptor and c3 receptors. 6) MPA and sorting of microcytospheres will yield biologic reagents that can test tumorigenic potential of non nuclear components of malignant cells. 7) Single lymphocytes of B or T origin can be sorted into microculture by means of MPA where activation and differentiation can then take place.